I like the various voice dialing options for the treo650 -- I've
used both the Sprint contact list and the SW solution offered by
PalmOne. However, it seems none of these are compatible with
interactive systems -- i. e., something as simple as dialing
extra digits. My old StarTac allowed me to store multiple
strings of extra digits and activate them in sequence by
pressing a side button. So far, I can only get my Treo (both
the 600 and 650) to dial a single string after the main number.

Is there a way to get a voice-dialing system to dial the primary
number and then activate a second dialing string? Even if it's
by hitting a button manually? Or better yet, a set of multiple
strings of digits -- sequentially?

Or is there some application that will dial pre-stored strings
of digits when pressing particular assigned buttons? THAT
would be VERY useful.

You can use commas to dial a second string of numbers. The commas add a second pause then the strings are dialed. I use this to access several different voicemail systems. You need to use the commas to separate the commands of the system as well.

Excellent - thanks! Odd I didn't see that anywhere. But is there some way of
introducing an actual stop that would require some manual action to
diall this second string? Maybe it's time for some experimenting, since
it seems to me they'd have used some standard algorithm in the treo
for this kind of stuff.